Collins COBUILD Advanced Learner's English Dictionary - efficiency

(efficiencies) 1. Efficiency is the quality of being able to do a task successfully, without wasting time or energy. There are many ways to increase agricultural efficiency in the poorer areas of the world. ...energy efficiency. N-UNCOUNT 2. In physics and engineering, efficiency is the ratio between the amount of energy a machine needs to make it work, and the amount it produces. (TECHNICAL) N-UNCOUNT: also N in pl